To integrate the image stabilization (VC) Tamron certainly had to adapt the optical formula a bit. So although I'd expect this macro to perform on a very high level, don't simply expect this lens to perform equal to its non-stabilized equivalent, the SP AF 90mm 2.8 Di Makro 1:1, which had the following technical data: Lens-elements/groups: 10/9; standard AF-motor; min focus distance: 0.29m; smallest aperture: f/32; filter-thread: 55mm; size (diam./length): 71.5 x 97 mm; weight: 405g, and is currently sold for around 400 EUR (incl. 19% VAT).As you can see the new lens has a more complex design with 14 elements in 11 groups vs. 10 elements in 9 groups.